From Mailchimp to Klaviyo: Our Client's eCommerce Growth Story

We recently onboarded a client doing seven figures in revenue. Their email marketing was contributing just 11% of that. They were on Mailchimp, sending a weekly campaign and running a basic abandoned cart flow.

They felt stuck. Revenue had plateaued. They knew email should be doing more, but couldn’t figure out how to make it happen inside Mailchimp’s walled garden.

This isn’t an uncommon story. I’ve seen it dozens of times. A brand grows, but its marketing tools don’t grow with it. This is the story of how we moved them to Klaviyo and more than doubled their email-generated revenue in 90 days.

The Mailchimp limitations that prompted a Klaviyo switch

The client’s frustration wasn’t with email marketing as a channel. It was with their platform. Mailchimp was built for sending newsletters. Modern eCommerce requires a data engine.

When we audited their account, we found the same core issues we see in almost every Mailchimp setup for a growing store.

First, the segmentation was basic. Mailchimp is built around static lists and tags. This makes it difficult to create dynamic, behaviour-based segments. They couldn’t target customers who bought a specific product but hadn’t returned in 90 days. They couldn’t separate high-AOV customers from discount-only buyers. Everyone got the same weekly campaign.

Second, the automations were rigid. Their welcome series was a single email. Their abandoned cart flow sent two reminders and gave up. There were no conditional splits. No way to treat a first-time visitor who abandoned a $300 cart differently from a repeat customer who abandoned a $50 cart. It was one-size-fits-all, which in eCommerce means one-size-fits-none.

The reporting was the biggest black box. Mailchimp could report on opens and clicks. It struggled to connect those actions to actual dollars in their Shopify account. They were flying blind, unable to say which emails were driving sales and which were just wasting time. This is a common problem for brands trying to get serious about their email marketing.

Finally, the platform was becoming expensive without providing more value. As their list grew, so did their monthly bill. But the features didn’t improve. They were paying more for the same limited toolkit that was holding them back. The trigger point wasn’t just one thing. It was the combination of flatlining revenue, a lack of actionable data, and a growing sense that their biggest marketing channel was working against them.

Our client’s strategic migration from Mailchimp to Klaviyo

Moving email platforms is a serious project. I’ve seen brands lose months of revenue from a botched migration. We follow a strict process to make sure that doesn’t happen. It’s not just about moving data. It’s about building a completely new foundation for growth.

Our first step is always a deep audit and strategy session. We mapped their entire customer journey. We identified key touchpoints where an email or SMS could make a difference. We defined the core segments they needed to build, not just the ones Mailchimp allowed. This formed the blueprint for the entire migration. This is a core part of our process for any new client engagement.

Data transfer and list hygiene

The most critical part of any migration is the data. We didn’t just dump their Mailchimp list into Klaviyo. We used the move as an opportunity for a deep clean.

We exported all subscriber data, including purchase history and any custom properties they had managed to create. Then we ran it through a hygiene process. We identified and suppressed subscribers who hadn’t opened an email in over 120 days. This immediately improved their deliverability and sender reputation. It also lowered their Klaviyo subscription cost from day one.

We ensured every piece of historical data from Shopify was synced correctly. This is something Klaviyo does natively and exceptionally well. Suddenly, we had every order, every product viewed, and every cart initiation tied to a specific profile. This data is the fuel for everything that comes next.

Building a robust segmentation strategy

With clean, rich data in place, we built the segments we had mapped out in our strategy phase. This is where Klaviyo leaves Mailchimp behind.

We started with the fundamentals: * VIPs: Customers with a high lifetime value (LTV). * Potential VIPs: Customers who have spent a certain amount but aren’t yet in the top tier. * One-Time Buyers: Customers who made a single purchase and never returned. * Repeat Buyers: Customers with two or more purchases. * Winback Candidates: Lapsed customers who haven’t purchased in 90 days. * Highly Engaged: Subscribers who open or click frequently but may not have purchased yet.

These dynamic segments are impossible to build and maintain properly in Mailchimp. In Klaviyo, they update in real-time based on customer behaviour. This work set the stage for true personalisation. We’ve written before about Why More Klaviyo Segments Don’t Always Mean More Revenue; it’s about building the right segments, not just more of them.

Reimagining core email flows

We didn’t just copy-paste their old automations. We rebuilt them from the ground up to use Klaviyo’s advanced capabilities.

The simple welcome email became a 5-step welcome flow. It had conditional splits based on whether a subscriber had browsed a specific category. It educated them about the brand, showcased social proof, and presented a strategic offer.

The abandoned cart flow was completely overhauled. It expanded to four emails and two SMS messages over 72 hours. It included dynamic content blocks showing the exact items left in the cart. It had different messaging for high-value vs low-value carts.

The post-purchase experience went from non-existent to a multi-step flow. It confirmed the order, set shipping expectations, requested a review, and introduced relevant cross-sell products based on their purchase. This turned a simple transactional email into a revenue-generating machine.

Immediate revenue uplift: Klaviyo’s impact post-migration

The results came faster than the client expected. The switch from Mailchimp to Klaviyo wasn’t just a technical change. It was a strategic shift that paid off immediately. Within the first three months, email-attributed revenue increased by 142%.

Owned revenue as a percentage of total store revenue jumped from 11% to 26%. This is the kind of impact that changes the economics of a business, reducing reliance on increasingly expensive paid acquisition. The numbers prove that focusing on retention and owned marketing is the most sustainable way to scale. You can see more examples of our results across other clients.

Welcome flow optimisation

The new welcome flow was a major contributor. The old Mailchimp email had a 22% open rate and a 1.2% click-through rate.

The new, multi-step Klaviyo welcome flow averaged a 45% open rate and a 4.8% click-through rate across all five emails. More importantly, the conversion rate for new subscribers who went through the flow was 5.4%. It became a consistent and predictable source of new customer revenue. This is the power of following a proven structure like The Elite Brands Framework for Your Klaviyo Welcome Flow.

Abandoned cart flow overhaul

This was the single biggest revenue driver. The old Mailchimp flow recovered just 4% of abandoned carts. It was barely worth having.

Our new Klaviyo flow, which included SMS, lifted the recovery rate to 13%. For a seven-figure brand, recovering an extra 9% of abandoned carts translates to tens of thousands of dollars in found revenue every month. The key was using Klaviyo’s tight Shopify integration to show product images directly in the email and sending a timely SMS nudge 60 minutes after the first email. Integrating SMS with Your Klaviyo Abandoned Cart Flow for Better Recovery is a tactic we deploy for nearly every client.

Post-purchase engagement and loyalty

The post-purchase flow wasn’t just about making another sale. It was about increasing customer lifetime value.

The review request email in the flow achieved a 12% response rate, feeding a steady stream of user-generated content to their product pages. The cross-sell email, sent 14 days after purchase, had a 3% conversion rate, adding significant incremental revenue. It worked because we could use Klaviyo’s data to recommend products that were genuinely complementary to their original purchase. This laid the groundwork for turning one-time buyers into loyal, repeat customers.

Leveraging Klaviyo’s advanced features for sustained growth

The initial 90-day lift was just the beginning. The real power of Klaviyo is its depth. After stabilising the core flows and campaigns, we moved on to more advanced strategies to ensure long-term, sustainable growth. This is where our Klaviyo expert team creates the most value.

We continue to manage the account, constantly testing and optimising. The migration isn’t the end of the project. It’s the start of a new growth phase.

Hyper-segmentation for precision targeting

With a few months of data in Klaviyo, we could get even more granular with our segmentation. We built a segment of “At-Risk Customers” who had a high predictive LTV but hadn’t purchased in their typical buying cycle.

We created a targeted 3-email campaign just for them. It acknowledged their past loyalty, offered a unique incentive, and highlighted new products we knew they’d like based on their purchase history. This single campaign reactivated 17% of the at-risk segment within two weeks.

Omnichannel marketing with SMS and push notifications

Email is the core, but Klaviyo allows you to orchestrate a true omnichannel experience. We expanded our use of SMS beyond the abandoned cart flow.

We implemented SMS campaigns for flash sales, getting time-sensitive offers in front of customers instantly. The open rates for SMS are consistently above 90%. We also set up transactional SMS messages for shipping notifications, which improved the customer experience and reduced “where is my order?” support tickets by over 30%.

Predictive analytics and customer lifetime value

Klaviyo’s built-in AI tools are incredibly powerful if you know how to use them. We use their predictive analytics to identify customers with the highest expected LTV. This informs our VIP strategy and even our ad spend.

We can create a segment of customers predicted to place their next order in the next week and sync it to Meta Ads. This allows us to create highly effective retargeting or lookalike audiences. It’s about using data to make smarter decisions across the entire marketing ecosystem. Klaviyo provides excellent documentation on their predictive analytics features for those who want to dig deeper.

Why Klaviyo is the best email platform for eCommerce

I get asked about the Klaviyo vs Mailchimp debate all the time. For a small hobby business or a local service company, Mailchimp is fine.

If you run an eCommerce brand and you are serious about growth, the choice is clear.

Klaviyo was built from the ground up for eCommerce. Its deep integration with Shopify, its revenue-centric reporting, and its powerful segmentation and automation tools are specifically designed to solve the problems that store owners face. Mailchimp was built to send emails. Klaviyo was built to generate revenue.

The case study I’ve just walked through is a perfect example. The client didn’t change their products. They didn’t drastically increase their ad spend. They just switched to a tool that allowed them to properly use their own customer data.

Of course, the platform is only half the battle. You need a clear strategy to make it work. The best tools in the hands of an inexperienced operator will still produce average results. But you cannot achieve exceptional results with a tool that fundamentally limits your strategy. Mailchimp is a ceiling. Klaviyo is a foundation.

If you feel like you’ve hit a ceiling with your current email platform, it might be time for a change. A good first step is to get an objective view of where you stand with a free Klaviyo audit.

If your email platform feels more like a cost centre than a revenue driver, we should have a conversation.